CA2261488A1

CA2261488A1 - Transabdominal device for performing closed-chest cardiac surgery

Info

Publication number: CA2261488A1
Application number: CA002261488A
Authority: CA
Inventors: Anthony Paolitto; Valerio Valentini; Raymond Cartier
Original assignee: Coroneo Inc
Current assignee: Coroneo Inc
Priority date: 1999-01-21
Filing date: 1999-01-21
Publication date: 2000-07-21
Also published as: US20080015408A1; US6478028B1; US7264000B2; US20110144438A1; US20030010346A1

Abstract

Surgical apparatus and devices are provided for performing closed chest cardiac surgery. A multi-lumen substantially tubular channel is inserted transabdominally to gain access to either the pleural or mediastinal space for the purposes of achieving less invasive cardiac surgery, more particularly complete revascularization CABG
surgery directly on the beating heart. The said channel includes provisions for setting heart positioning and orienting devices, coronary artery stabilization devices, cannulae, catheters and sensors. The channel also has a provision such as designated multiple lumens and compliant seals for the introduction and preservation of pressurized gases within the accessed cavity. The principles and design features can be utilized in beating heart bypass surgery, valvular surgery, and general cardiac repair surgery by providing a means of introducing desired materials, surgical instruments, instrumentation into the accessed cavities.

Description

FIELD OF THE INVENTION
The present invention relates to the field of cardiac surgery apparatus, and more specifically to the apparatus used in cardiac surgery performed directly on the beating heart.
In the present invention, the term "cardiac surgery" comprises the following types of surgery: coronary artery bypass graft surgery (CABG) performed directly on a beating heart (beating heart bypass surgery), CABG performed on an arrested heart (traditional l0 CABG), heart valve repair surgery or valve replacement surgery, and surgery to correct either an atrial septal wall or ventricular septal wall defect.
In the present invention the terms "device" , "cardiac devices", and "apparatus"
comprise the surgical apparatus, instrumentation, and devices utilized during cardiac surgery.
In the present invention the term "cardiac organs" comprises the heart, the heart's arteries and veins, the surrounding tissue and vessels, in particular the mediastinum, the pericardium, the thymus, the pleura, and the space between the two lungs.
In the present invention, the terms "closed chest" signifies a surgical intervention whereby the patient's thoracic structure TS (ribcage), and bone defining said thoracic structure, are not cut, broken, spread apart or substantially not displaced from their normal anatomical position and orientation.
BACKGROUND OF THE INVENTION
Cardiac surgery, and more specifically traditional CABG, has been performed since the 1970's on a regular basis with the support of the cardio-pulmonary machine, whereby the patient's blood is oxygenated outside the body, through extracorporeal circulation (ECC). The development of the cardio-pulmonary machine for ECC enables surgical interventions to take place on the arrested heart. This allows the surgeon to manipulate and operate on a perfectly still heart. The arrested heart can be positioned to expose and provide best access to the target artery requiring bypass grafting.

Traditional CABG is still referred to as the gold standard in coronary artery revascularization since it enables complete revascularization to be achieved, that is the treatment of all diseased arteries requiring bypass grafts. It thereby also reduces the likelihood of future surgical re-interventions, which reduces costs to the healthcare system and alleviates anxiety for the cardiac patient.
However, there are two main invasive aspects associated to traditional CABG -the sternotomy incision and the ECC.
Even with the constant technological improvements achieved during the last twenty-five years, the advantages offered with ECC have been offset by the morbidity (complications) and mortality related to the ECC itself. ECC represents the most invasive clinical aspect of traditional cardiac surgery, particularly in CABG
surgery.
The inflammatory response, as well as the systemic microembolisms generated by ECC, induce to some extent a dysfunctional state of the brain, lungs, and kidneys, which tends to increase with the aging of the patient. Furthermore, evidence suggests that when ECC can be avoided, the left ventricular function (pumping efficiency) of the heart is better preserved, thereby also reducing the risks of post-operative complications and the need for ventricular assist devices to wean the arrested heart back to normal function.
In addition to being the most invasive aspect of traditional CABG, ECC is also the most costly device to operate during this procedure.
Median sternotomy is less clinically invasive than ECC, but has the perception of being more invasive due to the surgical scaring that results from the surgery. Full median sternotomy can result in: temporary disturbance in the respiratory mechanism, increased risk of operative shock, dehiscence, and re-operation from bleeding complications. Moreover, long exposure of the mediastinum to air can lead to hypothermia, infection and compromise of the neuro-endocrine response.
Patients with severe chronic obstructive pulmonary disease (COPD) or severe emphezema or with severe pulmonary insufficiency are therefore at higher risk of complications when exposed to sternotomy incisions.
As a result, alternative CABG procedures that do not rely on the very invasive and costly use of ECC offer distinct advantages to both the patient and the progressively discriminating cost sensitive health care system. Furthermore, if the sternotomy

2 incision can also be eliminated this would offer distinct advantages in minimizing surgical scaring. An even further advantage can be realized, if complete revascularization can be achieved on the beating heart through closed chest approach since it not only manages healthcare costs incurred with future surgical interventions but also from the patient's perspective, the anxiety and inconvenience associated with future re-interventions.
In recent years, the drive for less invasive surgical apparatus and cost-effective medical approaches has placed emphasis on cardiac surgery as well. However, unlike l0 other organ surgeries, gall bladder for instance, the beating motion of the heart complicates the surgical intervention.
Port access surgery (HeartportTM) consists of replacing the full median sternotomy by a series of port incisions in the chest, through which coronary artery revascularization is performed. However, the most invasive aspect, ECC, is retained in this surgery.
Femoral cannulation and aortic cross-clamping must be performed to place patient on ECC. This approach also requires lung deflation to provide working volume and to access remote territories of the heart. Unlike traditional CABG, the heart cannot be "verticalized" with respect to the chest cavity in order to access the posterior territory.
2o Performing the surgery remotely through small ports is difficult, often leading to unwanted tissue dissection that requires the conversion to traditional CABG
through full sternotomy in order to complete the surgical procedure.
It would be advantageous to have a surgical apparatus and medical approach which maintains, as much as possible, the normal anatomical position and orientation of the heart during the surgical intervention. This invention replaces the unnatural verticalization required to access the posterior territory with the full sternotomy approach.
3o In minimally invasive direct coronary artery bypass graft surgery (MIDCAB), ECC is avoided and coronary artery revascularization is performed directly on the beating heart with the help of a mechanical stabilizer, through a mini-sternotomy or mini-thoracotomy incision. This surgical approach allows access to only one or two of the anterior arteries of the heart, most commonly the left anterior descending artery (LAD).
Demographically only 5-15% of the population is afflicted with single vessel disease;
the majority of cardiac patients (70%) suffer from triple vessel disease, whereby at least one artery on each of the anterior, inferior and posterior territories of the heart

3 requires a bypass graft. As a result, this approach is also referred to as "limited access bypass surgery".
The beating heart approach employed with mechanical stabilization has also been developed to enable grafting of the difficult to access posterior arteries, such that complete revascularization can be achieved on the beating heart. One such surgical device that immobilizes a portion of the beating heart around the target artery, and helps "verticalize" the beating heart is described in Canadian Patent Application 2,216,893 filed by Cartier and Paolitto, entitled "Sternum Retractor for Performing Bypass Surgery on a Beating Heart". A median sternotomy is required in order for the apex of the "verticalized" beating heart to clear the ribcage while exposing the posterior territory. Although less invasive than ECC, the sternotomy incision with its associated complications is retained in this approach.
Percutaneous transluminal angioplasty (PCTA) or Coronary Stenting are intraluminal surgical procedures which achieve coronary artery revascularization through the enlarging of restricted vessels by balloon angioplasty (PTCA) and in some cases also supplemented by the scaffolding effect of the tubular mesh stent. Sternotomy incisions and ECC are avoided since the entire procedure takes place through the patient's artery. However, the high incidence off restenosis (repeat restriction of the artery), and its inapplicability to triple vessel disease does not make this procedure suitable to the majority of cardiac patients that require complete revascularization.
Other emerging technologies, such as Transmyocardial Revascularization (TMR) or Percutaneous Myocardial Revascularization (PMR) are reserved for non-reconstructible disease.
For the great majority of patients, those with triple vessel disease, the aim of any coronary revascularization cardiac surgery is to achieve complete revascularization.
That is, the revascularization of all diseased arteries in the least invasive manner. The aim is to overcome the limitations in current approaches, which at the expense of a less invasive intervention compromise the thoroughness or completeness of the surgical procedure. This limits the likelihood of re-intervention in approaches where the benefits are short-lived (restenosis associated with PTCA and Stenting) or the disease progresses in areas of the heart that were inaccessible at the first intervention (limitations associated with surgical apparatus and technique).

4 It would therefore be advantageous to provide a surgical approach and associated apparatus that can cater to the entire demographically representative group of patients without the invasive aspects of ECC and median sternotomy, that achieves complete revascularization.
It would be a further advantage if this surgical approach and associated surgical apparatus is cost effective in lowering the initial healthcare costs of the procedure and minimizing future costs by reducing likelihood of re-intervention.
This invention describes a surgical apparatus that allows the manipulation and positioning of the beating heart, along with the deployment of coronary stabilizers that serve to immobilize a portion of the beating heart around the target artery, through a transabdominal tunnel, thereby allowing complete revascularization without the invasiveness of ECC and sternotomy incision. The grafting is either performed through additional ports through the patient's chest or through the same transabdominal tunnel. Stereoscopic camera lenses, that transmit images to the surgeon so that closed chest interventions can be performed remotely, are placed at the distal surgical worksite either through the transabdominal tunnel or through additional port incisions in the patient's chest. Carbon dioxide is used to displace abdominal organs in deployment of the transabdominal tunnel or to prevent air embolisms in the chest cavity during the revascularization procedure. Passages in the transabdominal tunnel are provided for the channeling of carbon dioxide gas.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to improve the efficacy and safety of cardiac surgery, more specifically CABG, by providing a surgical apparatus that eliminates ECC, and achieves complete revascularization directly on the beating heart through a closed chest approach, more specifically without sternotomy incision.
It is a further object of the present invention to improve safety of the cardiac surgery, more specifically CABG, by providing a surgical apparatus that improves the surgical outcome for the patient.
It is therefore a further object of the present invention to provide a surgical apparatus which allows cardiac surgery, more specifically CABG, while eliminating the likelihood

5 of bone breakage or bone displacement associated with traditional sternotomy or thoracotomy heart exposure.
It is therefore a further object of the present invention to provide a surgical apparatus that expands the patient base for traditional CABG, more specifically by including patients with severe COPD, severe emphezema, severe pulmonary insufficiency.
It is therefore a further object of the present invention to provide a surgical apparatus that allows cardiac surgery, more specifically CABG, while decreasing the risks of l0 operative shock associated with traditional CABG.
It is a further object of the present invention to provide a surgical apparatus that decreases the initial cost of cardiac surgery, more specifically CABG, and futute costs of surgical re-intervention associated with the limitations of alternative coronary artery revascularization surgeries.
It is a further object of the present invention to position and orient the beating heart through a device acting on a distal remote location away from the target work-site on said beating heart where the surgical intervention is to be performed.
It is a further object of the present invention to improve the invasiveness of beating heart CABG, by providing a means of positioning and orienting the beating heart without impeding or restricting the natural beating function of the heart.
It is an additional object of the present invention to apply the concepts and principles of this invention as they relate to beating heart CABG to other types of cardiac surgeries.
BRIEF DESCRIPTION OF THE DRAWINGS
3o The invention will further be described, by way of example only, with reference to the accompanying drawings wherein:
Figure 1 - is a frontal view of the patient with sectioned thoracic cavity illustrating preferred embodiment according to the present invention;
Figure 2 is a partial sectional view illustrating the insertion of a laparascopic cannula to create a sagittal tunnel towards the diaphragm;

6 Figure 3A is a sectional view of the patient's thorax, illustrating the multi-lumen channel 10 and heart manipulator 20 prior to C02 insufflation into the pleural space;
Figure 3B is a sectional view of the patient's thorax, illustrating the transabdominal device 1 after C02 insufflation into the pleural space;
l0 Figure 4 is a sectional view of the diaphragm tissue retractor 40 in closed position within the extraperitoneal space;
Figure 5A is a sectional view of the diaphragm tissue retractor in deployed , position with multi-lumen channel 10 inserted within;
Figure 5B is a partial sectional view of the multi-lumen channel 10 engaged with the diaphragm accessing the pleural space, and of the channel clamp 510;
Figure 6 is a partial sectional view through a portion of the securing platform 50;
Figure 7 is longitudinal sectional view illustrating the transabdominal device engaged with the apex of the beating heart during CABG surgery;
Figure 8A is a traverse sectional view through the multi-lumen channel 10 illustrating the HML and PAL and a open ended clamp variant for the articulation mechanism 170;
Figure 8B is a traverse sectional view through the multi-lumen channel 10 illustrating a multi lumen variant of said channel and a closed clamp variant for the articulation mechanism 170;
Figure 9 is longitudinal sectional view of the heart manipulator 20;
Figure 10 is a perspective view of the coronary stabilizer 30;

7 Figure 11A is a perspective view of the transabdominal device 1 deployed to provide surgical intervention on the posterior territory of the beating heart;
Figure 11 B is a perspective view of the transabdominal device 1 deployed to provide surgical intervention on the anterior territory of the beating heart;
Figure 12 is a partial sectional view exposing the pleural space and illustrating l0 a pericardium retraction device 69 inserted through the PAL of multi-lumen channel 10 to assist in positioning the beating heart during posterior artery CABG surgery.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
is The present invention reduces the invasiveness of cardiac surgery, more specifically CABG surgery, while also reducing associated initial and future healthcare costs, by providing a device which enables closed chest, beating heart coronary artery revascularization.
The patient's beating heart is positioned and oriented through a multi-luminal transabdominal device (MLTAD). Subsequent surgical interventions can then be performed through at least a section of said transabdominal tunnel or alternatively through additional port incisions through the patients closed chest.
The features and principles of this invention can be applied, in whole or in part, to other types of cardiac surgery requiring the strategic positioning and orientation of the heart and transabdominal introduction of surgical apparatus within the closed chest pleural space, but the description of the preferred embodiments will focus on beating heart CABG surgery.
In broad terms, the surgical procedure for the set-up and deployment of the surgical apparatus relating to this invention consists of:
1. Stereoscopic camera lens inserted into the pleural space via a port incision between the patients ribs;
2. Single lung deflation, preferably the left lung, is performed to augment the closed-chest pleural space (PLS) -- surgical work space;

8 3. Abdominal incision (AI) is performed in the left upper quadrant of the patient;

4. Insertion of a laparoscopic cannula into the abdominal incision to reach the extra-peritoneal space (EPS);

5. Carbon dioxide insufflation via the laparoscopic cannula to assist the dissection of the extra-peritoneal space, and laterally displace the viceral organs (VO) contained within the peritoneum (PER);

6. From the site of the abdominal incision, creation of an upward sagittal tunnel to access the diaphragm (DG), preferably at the left leaflet location;

7. Insertion of a guide wire through the center of laparoscopic cannula, up the sagittal tunnel, through the diaphragm, to attain the pleural space;

8. Over the guide wire, slide an enlarging cannula with conical tip that progressively enlarges the diaphragm (Seldinger Approach);

9. Over the enlarging cannula, slide a diaphragm tissue retractor 40 that pierces through the diaphragm and creates an opening through its subsequent radial deployment;

10. Once the desired opening is achieved in the diaphragm, slide through the center of the diaphragm retractor 40, the multi-lumen channel 10 in a manner that its distal end is now in communication with the pleural space;

11. Retrieve the diaphragm retractor leaving the perimeter of the retracted diaphragm tissue engaged with the multi-lumen channel 10;

12. In order to further augment the surgical work space, carbon dioxide is channeled into the closed chest pleural space thereby forcing downward the dome of the diaphragm, along with the engaged multi-lumen channel 10;

13. Secure channel 10 to the surgical table via securing platform 50;

14. If the internal mammary artery (IMA) is required for a bypass graft, proceed to surgical harvesting of the IMA by inserting a cauterizing scalpel or ultrasonic cutter through one of the pleural access lumens (PAL) in the multi-lumen channel 10;

15. With the surgical harvesting of the IMA completed, also incise the pericardium tissue of the beating heart to expose the myocardium, and retrieve the ultrasonic cutter;

16. Through the heart manipulation lumen (HML) of channel 10, engage a portion of the heart, preferably the apex, with the heart manipulator 20;

17. Rotate multi-lumen channel 10 with respect to the centerline of its HML, to obtain the best exposure and access to the desired coronary artery territory via the eccentric PAL;

18. Distally position and orient the beating heart attached to the heart manipulator, through extracorporeal proximal movement of manipulation handle;

19. Deploy the coronary stabilizer 30 through the multi-lumen channel 10, into the pleural space, to attain the desired configuration for the specific artery requiring grafting;

20. Place the coronary stabilizer on the myocardium thereby immobilizing the portion of the beating heart around the target artery to be grafted;

21. Once immobilization is achieved, secure the coronary stabilizer with respect to the multi-lumen channel 10;

22. With help of stereoscopic vision, perform closed-chest anastomosis either through trans-thoracic ports between the patient's ribs, or transabdominally through the access lumen in channel 10;

23. Once the anastomosis is completed, retrieve coronary stabilizer and repeat procedure (steps 16 - 21) for the other arteries, if multi vessel CABG is performed;

24. Once all diseased arteries are revascularized, retrieve all components of the transabdominal device 1, and proceed to closing all incisions via standard medical practice.
In the preferred embodiment according to this invention, the transabdominal device TAD 1, is comprised of a multi-lumen channel 10, a heart manipulator 20, a coronary stabilizer 30, diaphragm tissue retractor 40, a securing platform 50, and thoracoscopic surgical instruments 60 (Figure 1).
The diaphragm tissue retractor 40 is comprised of a hollow inner body 460, tissue-retracting petals 410, a translating sleeve 440, and a deployment lever 430 activated outside the patient's body (Figure 4). The diaphragm is pierced firstly by the guide wire 400, and subsequently distended by enlarging cannula 402 configured with a tissue piercing tip 401. The distal end of the inner body 460 is configured with a plurality of tissue retracting petals 410 which, in their closed position, form a conical leading end profile with a hollow tip well suited to being insertable and slidable over the enlarging cannula 402. The cylindrical tip 411, formed by the tissue retracting petals in their closed position, engages between the perimeter of pierced diaphragm and the outer diameter of the enlarging cannula 402. Each portion of the petals forming said cylindrical tip 411 is deployed radially outward to enlarge the starting orifice in the diaphragm to the desired opening, thereby capable of receiving the multi-lumen l0 channel 10 (Figure 5A). Deployment is achieved through lever 430 which displaces a translating sleeve 440 with a sliding fit 441 over the exterior of inner body 460, thereby engaging the cam like interface 445 and 415 between the retracting petals and the said translating sleeve. The radially inward force from the cam interface rotates each of the petals about hinge 420, thereby retracting the diaphragm tissue. Unlike the Seldinger method of gradually increasing the opening in tissue by progressive insertion of a conical tip cannula, the present embodiment allows the significant enlargement of the diaphragm orifice without risk of injury to the above-lying thoracic organs, that would likely result if an enlarging cannula would be used exclusively.
Once the diaphragm tissue has been retracted, the multi-lumen channel 10 is inserted through the hollow inner body 460. The permanent weir 130 extends past the end of the retracting petals 410. Subsequently, the deployment lever 430 is released, the petals and diaphragm tissue contract slightly and the tissue retractor 40 is retrieved from the body. This results in the diaphragm engaged around the distal end of multi lumen channel 10, upstream from the permanent weir. This configuration is beneficial since it allows the said channel 10 to mechanically pull down on the engaged diaphragm, or if C02 will be inserted within the pleural space, the pressure loads on said channel 10 will maintain it engaged with the diaphragm through the permanent weir 130.
C02 can be introduced into the pleural space either through a lumen in channel 10, or alternatively through a trans-thoracic port. The pressurized C02 serves to augment the pleural space by pushing down on the dome of the diaphragm, and consequently through the permanent weir which serves as a axial buttress, the said channel 10 also moves down and out of the body, leaving a shorter length of engaged channel within the body.
Channel 10 may be configured with a fastened proximal end 110, that can at this point be removed to yield a more ergonomic extracorporeal work space. The resulting shorter length channel 10 allows more angular range in articulation of instruments that may be inserted through said channel during surgery.
Fastened interface 111 may be threaded, bayoneted, detented, wedged or of any other quick assembly interface.

In order for the pleural space to remain pressurized with C02, all lumens within said channel 10 are provided with a seal, preferably but not limited to a diaphragm type seal. In the preferred embodiment, the seal 160 is a membrane with a plurality of nipples 161, through which a variety of surgical instruments may be easily inserted either before or during surgery, more specifically the heart manipulator 20 and coronary stabilizer 30 (Figure 7).
Once engaged with the diaphragm, and C02 pressurization of the pleural space has been introduced (if desired), said channel 10 is positioned and oriented with respect to to the patient's body, and more specifically the cardiac organs that will be subject to the surgical intervention. This level of adjustment is referred to as "coarse adjustment".
Multi-lumen channel 10 is secured in any substantially stable position and orientation relative to the surgical table 3, via securing platform 50. Said platform 50 is comprised of a channel clamp 510, an articulation rod assembly 540, and a table clamp (Figure 5A and 5B) The preferred embodiment of the channel clamp 510 comprises a set of three discs 511, 512, 513 whose inner diameters match the outer diameter 101 of the multi-lumen channel 10, such that the said discs can be slidingly rotated over said outer diameter 101. Disc 512 is also rotatably engaged to discs 511 and 513 through eccentric shoulders 514 and 515 protruding from both faces of disc 512. A rotation of disc 512, relative to discs 511 and 513, will radially offset disc 512 relative to said discs 511 and 513, to the extent that the three discs will place the multi-lumen channel 10 in shear, thereby achieving the desired clamping. Clamping techniques such as just described are commonly used in shafting design. The outer discs 511 and 513 are permanently attached to a 'U' shaped block 516 such that the inner portion of the 'U' does not come in contact with disc 512. Block 516 is permanently attached to a support rod 517 that has a sphere 518 at the end opposite to block 516. The sphere is pivotingly engaged in socket 550 such that the channel clamp 510 is free to rotate and pivot about the center point of said sphere within the conical limits defined by the surface 542 of nut 541.
when nut 541 is loose.
The end of articulation rod 543, closest to table clamp 570, has another socket 560 that rotatably engages sphere 571 of table clamp 570. The location of hole 561 in nut 560 is strategically placed to give optimum positioning of the articulation rod assembly 540 and channel clamp 510 with respect to the patient. The sphere 571 is permanently attached to the clamp block 572 via rod 573. Articulation rod assembly 540 is free to rotate and pivot about the center point of sphere 571 within the conical limits defined by the surface 563 of nut 562, when said nut is loose. Clamp block 572 is secured to the surgical table 3 by tightening at least one screw 574 with the aid of pivoted handle 575.
In addition to the present degrees of freedom allowed by the preferred embodiment, an additional degree of freedom can be obtained by making articulation rod 543 of variable length.
l0 Alternatively, the clamping method at joints 550 and 580 can be pneumatic, hydraulic, electromechanical, or magnetic.
Alternatively, the channel clamp 510 with any other portion of the securing platform 50 can be attached to a surgical robot instead of the surgical table.
In the preferred embodiment, the inside of channel 10 is configured with at least one hollow lumen that is substantially sealed to prevent pressure communication between the patient's pleural space and extracorporeal atmosphere. The heart manipulator occupies at least a portion of the hollow lumen, and the coronary stabilizer 30 at least another portion of said lumen.
Alternatively, said channel 10 can be configured with two designated lumens (Figure 8A); the HML lumen reserved for the heart manipulator, and the PAL lumen providing access to the pleural space and primarily occupied by the coronary stabilizer during beating heart CABG surgery. The PAL lumen, preferably when the coronary stabilizer is not occupying lumen, can be used provide access to the pleural space for the instruments used in the following surgical interventions: (i) IMA harvesting, (ii) incision of the pericardium sac, (iii) transabdominal port anastomosis, (iv) insertion of vascular conduit in bypass surgery, (v) doppler patency verification of newly-grafted vascular conduit, and (vi) assist in heart positioning and orientation through pericardium retraction sutures.
Alternatively, a plurality of lumens 125 (Figure 8B), each for a designated purpose can be incorporated for any combination of the above outlined (i) to (vi) surgical interventions. Designated lumens 120 are also possible for surgical services such as C02 pressurization of pleural space , illumination of the closed chest cavity through fiber optic bundle, and visioning of closed cavity through stereoscopic camera lenses (Figure 8A).
Figure 12 illustrates a pericardium retraction device 69 inserted through the PAL of channel 10. In order to assist in positioning and orienting the beating heart during posterior revascularizations, a suture 67 can be placed through the incised pericardium tissue 68, and pericardium traction applied through the said device 69. This helps to lift the heart within the thoracic cavity. The amount of protrusion of device 69 along with its fine adjustment position and orientation with respect to the channel 10 will determine the vector direction of the pericardium retraction load applied through suture 67.
Figure 7 illustrates a sectional view through multi-lumen channel 10, with the heart manipulator 20 and coronary stabilizer 30 assembled.
Once the multi-lumen channel is secured with the channel clamp 510, the heart manipulator 20 is preferably deployed before the coronary stabilizer. Heart manipulator is comprised of heart contacting member 200, conduit member 220, and detachable handle 240 (Figure 9).
Heart tissue engaging member 200 is comprised of flexible polymer substantially-conical sheath 204, detachable from hollow conduit member 220 through a barb fitting interface formed by mating members 202 and 222.
Member 200 engages with the beating heart, preferably the apex, through negative pressure.
Sheath 204 may be embodied with structural ribs 201 to bias the stiffness of said sheath in certain directions, thereby serving to facilitate the interface with the beating heart when negative pressure is applied through hollow passage 223 in conduit means 220.
Alternatively, sheath 204 can be designed to have variable elastic properties either by function of its thickness or by its variable composition in fabrication.
Reinforcement fibers can also be used in the fabrication of the polymeric sheath to bias its elasticity along certain axes. This is especially beneficial in the embodiment where the conduit means 220 is rigid, whereby 204 acts as a buffer in elastic gradient and encourages the deforming beating heart to remain in compliant contact with perimeter 205 of said sheath.
The contact perimeter 205 is configured with a tapered beveled edge, deformable skirt 203. This deformable skirt achieves a compliant seal perimeter 205, regardless of the beating heart's spatial orientation.
The deformable skirt 203 provides local readjustment of the plane formed by the perimeter 205 depending on how loads are applied to and reacted by the beating heart.
Any manipulation force applied in a direction substantially parallel to the axis of 220, the beveled edge distorts equally around the perimeter, in a direction toward the opening of said perimeter. If the force is applied in a skewed direction relative to the axis of conduit means 220, the beveled edge will distort unevenly around the perimeter in a fashion to replicate a plane substantially perpendicular to direction of application of said manipulation force or heart reaction force to imposed negative pressure loads.
Alternatively, can have plurality of conical sheaths 204 fed by a common negative pressure conduit 220.
Alternatively, the heart contacting member 200 can be comprised of a mechanical tissue clamping means, of a hydrogel or tissue adhesive-like coating or layer disengaged by positive pressure through 220, of a hemi-cylindrical cradle with perforations to allow anchoring of a suture to the apex tissue, of a non flowing static suction cup.
The outer diameter of conduit member 220, when detachable handle 240 is removed, allows its insertion into the articulation joint 170 of multi lumen channel 10.
The proximal end of 220 has barb fitting suction interface 221, that mates with the negative pressure source available in operating rooms.
The heart manipulator 20 can be positioned and oriented with respect to the multi-lumen channel 10. This position and orientation will be referred to as "fine adjustment".
The motion degrees of freedom that yield this fine adjustment are required to first enable engagement of the heart contacting member 200 with the desired portion of the heart, and subsequently are required to allow re-positioning and re-orientation of engaged heart during surgery with respect to the patient's thoracic cavity. In this manner, all coronary territories are accessible by the coronary stabilizer 30, with heart being located strategically within pleural space More specifically these motion degrees of freedom allow conduit 220 to be slidingly and pivotingly engaged through articulation mechanism 170.
The articulation mechanism 170 is insertable transversally through channel 10, thereby facilitating cleaning and sterilization if re-usable components are used. Said articulation mechanism is comprised of knob 190, two mating jaws 191 that when l0 engaged together form a longitudinal cylindrical surface that can rotate within bushing 192. Each jaw is provided with a hemi-cylindrical surface 193, such that when mating jaws engage, said hemi-cylindrical surfaces can apply a substantially diametrical clamping load to the outer diameter of the therewithin contained articulation cylinder 194. A cylindrical passage 195, perpendicular to the centerline of the articulation cylinder 194, is provided to receive the conduit 220. The surface of the cylindrical passage 195 is interrupted by at least one substantially longitudinal split 196, such that the clamping load imposed by the jaws on the puck will be transmitted to the outer diameter of conduit member 220.
Articulation mechanism 170 allows all the required degrees of freedom, at least 4., that is: the translation through articulation cylinder 194 of member 220 along the axis of said member 220, the rotation within cylinder 194 of member 220 about its centerline, the articulation of member 220 about the centerline of articulation cylinder 194, and the pivoting of member 220 about the cylinder of thread 197. Once the desired position and orientation of manipulator 20 is achieved, the fine adjustment is secured via knob 190 external to the multi-lumen channel 10.
The same articulation mechanism 170 can be employed for the coronary stabilizer 30, but it acts on the outer surface of proximal shaft means 360.
Figure 8A illustrates a variant to the articulation mechanism 170, that is, an open-ended clamp design that allows the transverse insertion of a shaft member on surgical instrument to be inserted through lumen of channel 10. This is advantageous if want to substitute surgical devices inside the lumen of channel 10 without wanting to disrupt the bulk of the surgical set-up.

Once the heart has been positioned and oriented by the heart manipulator, the multi-lumen channel 10 is rotated such that the eccentric access lumen, or the portion of lumen not obstructed by the manipulator, is aligned with the target coronary territory.
Figure 11 B shows the device deployed for anterior artery revascularization;
the access lumen in the top half of the channel 10, the beating heart oriented downward.
Figure 11A shows the device deployed for the posterior artery revascularization; the access lumen on the bottom half of the channel, the beating heart oriented upward.
The same applies for any coronary artery regardless of its location on the heart; the channel is rotated in such a manner to always offer optimum access and surgical approach of the l0 coronary stabilizer to the target artery. The present invention, therefore allows the synergistic deployment of the surgical apparatus -- the channel 10 is always positioned with respect to the heart manipulator, and more specifically its heart manipulation lumen (HML) as a function of the desired pleural access lumen (PAL).
The fine adjustment of the coronary stabilizer 30, that is of the proximal shaft member 360 with respect to multi-lumen channel 10, is achieved in the same manner as the heart manipulator 20, and secured through knob 190. Rotation C about the center line of proximal rod 360 is through the rotation of 360 within passage 195 of articulation cylinder 194.
The coronary stabilizer 30 is comprised of three main subassemblies (Figure 10): (i) extracorporeal control section, proximal to the surgeon (371, 331, 387, 386, 380, 385);
(ii) the heart contacting section, within the closed chest cavity, distal to the surgeon (300, 310, 320, 321, 322, 330, 341); and (iii) the center adjustment assembly (340,350, 351, 360, 361, 362, 370) for transmitting the surgeon's desired manipulation from the control section to the heart-contacting section.
The control section comprises a securing bolt 385, and a multi-socket cradle 380. The cradle is machined with three smaller diameter spherical sockets to interface with the 3o proximal sphere ends (not shown) of the articulation transmission cables 340. These interfaces with the cables can be permanently engaged by flaring the perimeter of the concave spherical surface in cradle around the sphere end of the cable, or easily disassembled if cradle is made from a resilient material or of a snap-in"
design.
The cradle 380 is also machined with a larger central spherical socket to interface with the substantially spherical end (not shown) of the inner rod 386. The perimeter of this concave spherical surface is flared only locally in three locations. The substantially spherical end of inner rod 170 has three flats that allow it to be insertable past the flared edge of the cradle. The cradle is then rotated approximately 60 degrees with respect to the centerline of rod 386, thereby achieving its fully assembled position.
This allows all the movements of a spherical joint with the two components slidingly linked in one assembly. The inner rod 386 has three longitudinal grooves, machined along most of its length, to serve as channels for the transmission cables 340.
The center socket in cradle 380 is pierced by a small threaded hole, at its topmost point, to receive securing bolt 385. This bolt exerts a force on the spherical end of rod 170, thereby clamping the spherical end against the flared edges of the cradle 380.
This results in a locked assembly through an action / reaction mechanism.
Loosening the bolt 385 permits sliding at the spherical interface, and repositioning of articulation transmission cables 340.
An annular brace 387 is inserted over the inner rod 386, to retain the cables 340 within their longitudinal grooves at the top, proximal location. A similar brace (not shown) can be inserted at the heart-contacting section of the coronary stabilizer 30.
The distal spherical ends 341 are engaged to the quick assembly / disassembly interfaces 321 on contacting member 300. The contacting member can be made from disposable surgical grade plastic, or any re-usable material such as titanium or stainless steel. The interface is specially designed to allow quick changeover to a variety of different contacting members (surgical kit) specific for different arteries, or to facilitate insertion of coronary stabilizer through multi-lumen channel 10 prior to insertion of said channel 10 into patient's pleural space.
The substantially planar surface of the contacting member 300 is positioned and oriented with respect to the distal shaft member 350, partly through the three-point interface 321 on plate member 320 responding to cradle 395 movement. This type of micro-adjustment produces:
e: rotation of contacting plane in a heel to toe" articulation E: rotation of contacting plane in a "side to sidep orientation The contacting member 300 is secured in its articulated and oriented state through the tightening of bolt 385.
The design of the preferred embodiment achieves the following i) remote response of the heart-contacting member 300 by movement of the proximal control cradle 380 ii) "active" readjustment of the contacting pressures for optimum coronary artery immobilization during "in-process" surgical variations, without disrupting fine and coarse adjustments The preferred embodiment also allows additional adjustment to set angle A.
This allows the heart contacting member 300 to be set in a position substantially offset from the centerline of the multi-lumen channel 10, in order to access and immobilize target arteries on the widest portions of the beating heart. The rotation of dial 371, through a sliding member (not shown) within the proximal shaft member 360, translates elbow 370 within slot 362. As a result, shaft member 350 rotates about hinge 36~ tn the desired angle A. The eccentricity of distal hinge 351 with respect to proximal hinge 361 results in a bias direction of rotation when applying the torque to dial 371.
The preferred embodiment also allows additional adjustment to set angle B.
This allows the rotation of the contacting member 300 with respect to the plate member 320, or the angular orientation of the arterial window 305 with respect to the centerline of shaft member 350, in order to better access target arteries that are diagonal in orientation with respect to the long axis of the heart. Rotation of dial 331 acts on a fourth return transmission cable 330, which in turn applies a torque on shaft attached to the contacting member 300. Shaft 323 rotates within bushing 322.
The coronary stabilizer 30 must react only the local forces from the underlying myocardium that it immobilizes; the loads from positioning and orienting the entire beating heart within the pleural space are reacted by the more robust heart manipulator 30.
To achieve a bloodless surgical field during beating heart bypass surgery, the heart contacting member is configured with wire attachment pedestals 315, located on opposite side of the arterial window 305, to anchor a vessel occluding wire 303, preferably a silastic loop. One said wire circumvents the target artery upstream and another downstream of the grafting site. Each end of the wire is inserted in a pedestal slit, said pedestals on opposite sides of the arterial window. The said slits achieve light-tight anchoring of the vessel occluding wire, thereby allowing non-traumatic disengagement of said wire in the eventuality of unwanted slippage of surgical apparatus or unwanted movement of the beating heart. The wire attachment pedestals are described in Canadian Patent Application 2,216,893 filed by Cartier and Paolitto, entitled aSternum Retractor for Performing Bypass Surgery on a Beating Heart".
The vessel occluding wire 303 is generally attached to a blunted needle. The circumventing of the target artery, and the subsequent anchoring of the wire in the pedestals 315, can be done either through traps-thoracic ports between the patient's ribs or through an pleural access lumen of multi-lumen channel 10. Similarly, the anastomosis of the vessel graft can be done either through traps-thoracic port access or transabdominally. In either case, the stereoscopic camera will allow the surgeon to l0 view his or her movements within the closed chest cavity.
Due to the preferred embodiments of the present invention, traps-thoracic port interventions are greatly simplified, more ergonomic, and less traumatic for the patient since the positioning and orientation of the beating heart and coronary artery immobilization are done transabdominally.
In the preferred embodiments according to the present invention, access to the pleural space was achieved by piercing at least a portion of the diaphragm.
Alternatively, the concepts and principles can also be applied to thoraco-phrenic dissociation surgical approach, whereby access to the pleural space is achieved through a passage between the diaphragm and the patient's ribcage without piercing the diaphragm.
In the preferred embodiments according to the present invention, access to the diaphragm and subsequently the pleural space was achieved via the extraperitoneal space. Alternatively, the concepts and principles can also be applied to intraperitoneal surgical approach in which at least a portion of the patient's peritoneal membrane is pierced.
In all embodiments herein described, the novel concepts and design features may also apply to other types of cardiac surgery. For example, the transabdominal device 1 can be applied to mitral valve replacement surgery. The right lung is deflated to augment closed chest pleural work space. The patient is placed on total cardiopulmonary bypass by femoro-femoral cannulation. A sub-xiphoid process incision, followed by incision of the pericardium will yield access to the patient's ascending aorta and thereby exposure for aortic cross-clamping. Hypothermia surgical environment helps support fibrillating heart which is relieved of its pumping requirement by cardiopulmonary bypass. Through the multi-lumen channel 10 inserted in the sub-xiphoid process incision, can be introduced within the pleural space the following: C02 gas, suction line, stereoscopic vision camera port, illuminating fiber optic bundle, cardioplegia infusion cannula, valve tissue retractor, and replacement valve.
The replacement valve annulus may be secured through trans-thoracic port approach.
Similarly, the same principles apply to atrial septal defect or ventricular septal defect repair cardiac surgery.
In all embodiments described herein, the bulk of the surgical apparatus is designed for totally reusable components, whose assembly can be totally dismantled, if necessary, to for ease of sterilization. All components are manufactured in either surgical grade stainless steel, titanium, aluminum or any other reusable sterilizable material.
Polymeric components are either reusable through specific sterilization procedures tailored to these components, or must be replaced after every use or predetermined number of uses. However, any number of the said reusable components can also be made in disposable surgical grade plastics, if the case for disposable components is warranted.
The above description of the preferred embodiments should not be interpreted in any limiting manner since variations and refinements are possible without departing from the spirit of the invention.

Claims

We claim:

1. A transabdominal surgical apparatus for performing cardiac surgery, more specifically closed-chest beating heart CABG, comprising:
- a heart manipulator for setting the beating heart in any substantially stable position and orientation within the closed-chest pleural work space, through a negative pressure force applied to at least a portion of the said beating heart;
- a substantially hollow transabdominal channel configured with at least one access lumen to introduce said heart manipulator into closed-chest pleural workspace;
- a securing platform capable of setting said transabdominal channel in any substantially stable position and orientation with respect to said pleural work space and surgical table;
- said heart manipulator comprising:
- at least one tissue-engaging sheath capable of providing negative pressure suction force on at least a portion of the said beating heart;
- extracorporeal device manipulation handle, substantially proximal, capable of providing the surgeon the ability to set the beating heart once engagement with the tissue-engaging sheath is achieved;
- conduit member for communicating said negative pressure from the substantially proximal device source means to the substantially distal tissue-engaging sheath within the said pleural workspace;
- device source means for said negative pressure.
- said transabdominal channel comprising:
- at least one articulation mechanism for setting said heart manipulator in any substantially stable position and orientation with respect to said channel;
- said heart manipulator slidingly, pivotingly and rotatingly connectable to said transabdominal channel;
- said securing platform pivotally connectable to said surgical table.

2. A transabdominal surgical apparatus according to claim 1, wherein said transabdominal channel additionally introduces a coronary stabilizer into closed-chest pleural workspace;
- said coronary stabilizer capable of providing a mechanical force against at least a portion of the patient's beating heart according to its positioning with regard to said heart;
- said coronary stabilizer comprising:
- a heart contacting perimeter therebetween creating an arterial window;
- at least one set of wire attachment pedestals positioned on opposite sides of the target artery requiring grafting on said heart contacting perimeter;
- extracorporeal device manipulation handle, substantially proximal, capable of providing the surgeon the ability to reset the said contacting perimeter with respect to said beating heart once engagement with the said beating heart is achieved;
- substantially hollow housing containing therewithin at least one articulation cable to transmit the surgeon's desired manipulation from said handle to said contacting perimeter within plearal work space;
- a vessel occluding wire insertable into said attachment pedestal to provide vessel occlusion of target artery during beating heart surgery

3. A transabdominal surgical apparatus according to claims 1 and 2, wherein said transabdominal channel comprises a substantial seal between its distal lumen accessing the pleural work space and its proximal end exposed to extracorporeal environment; said channel further comprising a designated pressurized lumen for CO2 insufflation within the pleural work space.

4. A transabdominal surgical apparatus according to claims 1 - 3 further comprising a designated lumen for pleural workspace stereoscopic vision and illumination through fiber optic bundling.

5. A transabdominal surgical apparatus according to claims 1 - 3 comprising a multitude of designated access lumens serving to introduce a variety of cardiac surgery instruments within the pleural work space.

6. A transabdominal surgical apparatus for performing cardiac surgery, more specifically closed-chest valve surgery, comprising:
- a heart manipulator for setting the heart in any substantially stable position and orientation within the closed-chest pleural work space, through a negative pressure force applied to at least a portion of the said beating heart;
- a substantially hollow transabdominal channel configured with at least one access lumen to introduce said heart manipulator into closed-chest pleural workspace along the necessary surgical instruments for valve surgery;
- a securing platform capable of setting said transabdominal channel in any substantially stable position and orientation with respect to said pleural work space and surgical table;
- said heart manipulator comprising:
- at least one tissue-engaging sheath capable of providing negative pressure suction force on at least a portion of the said beating heart;
- extracorporeal device manipulation handle, substantially proximal, capable of providing the surgeon the ability to set the heart once engagement with the tissue-engaging sheath is achieved;
- conduit member for communicating said negative pressure from the substantially proximal device source means to the substantially distal tissue-engaging sheath within the said pleural workspace;
- device source means for said negative pressure.
- said transabdominal channel comprising:
- at least one articulation mechanism for setting said heart manipulator and variety of valve surgery tools in any substantially stable position and orientation with respect to said channel;
- said heart manipulator slidingly, pivotingly and rotatingly connectable to said transabdominal channel;
- said securing platform pivotally connectable to said surgical table.